This pull request introduces a new test to detect a deadlock bug and includes modifications to handle connection write timeouts more robustly. The changes span across multiple files, with the primary focus on ensuring that sessions are closed properly when a write timeout occurs.

New Test for Deadlock Detection:

• deadlock_test.go: Added a comprehensive test TestTimeoutParallel to simulate and detect a deadlock scenario in yamux streams. This test sets up two streams, stalls one to fill the channel, and verifies if the session closes correctly on write timeout.

Improvements in Connection Write Timeout Handling:

• session.go: Enhanced the waitForSendErr and sendNoWait functions to ensure that the session is properly closed when a connection write timeout or session shutdown occurs. The changes include:
  • Adding deferred functions to call s.exitErr(err) if an error occurs. [1] [2] [3] [4]

Test Adjustments:

• session_test.go: Modified the TestSession_PingOfDeath to handle the expected ErrSessionShutdown error when a write times out, ensuring the test accounts for the new session shutdown behaviour.

Closes #142.

I humbly request a callout in changelogs when this bugfix ships :)